Economizer arrangement



May 9, 1967 GORZEGNO 3,318,290

ECONOMI ZER ARRANG EMENT Filed May 11, 1966 2 Sheets-Sheet 1 INVENTOR. WALTER P GORZEGNO ATTORNEY.

y 1967 w. P. GORZEGNO 3,318,290

ECONOMI ZER ARRANGEMENT Filed May 11, 1966 2 Sheets-Sheet 2 INVENTOR. WALTER I? GORZEGNO ATTORNEY United States Patent 3,318,290 ECONQMIZER ARRANGEMENT Walter P. Gorzegno, Florham Park, N..I., assignor to Foster Wheeler Oorporation, New York, N.Y., a corporation of New York Filed May 11, 1966, Ser. No. 549,343 9 Claims. (Cl. 122-510) This invention relates to vapor generators and the like and more particularly, an economizer arrangement in vapor generators and the like.

In the construction of vapor generators and the like, supports for horizontal convection tube banks have been located at each end or near each end of a horizontal run of tubes in the banks. Each of the vertical support walls or members to which these tubes attach should be essentially the same temperature to have a similar expansion. The span of a horizontal tube between these supports is dependent on tube material and temperature, and is limited by the tube deflection in the horizontal run. The allowable span may be increased by using stringer support members located about one-fifth of the total span from each end of the bank. This type of support for each pass results in four locations of stringer support tubes.

Therefore, it is an object of this invention to provide an economizer arrangement for use as a support for tube banks within a vapor generator or the like.

Another object of this invention is to provide support members at each end of the horizontal convection banks in a vapor generator, a combination of stringer and wall support, which support members are substantially at the same temperature during all periods of operation including start up and load changes.

In accordance with this invention, an economizer is provided which provides a substantial increase in the permissable horizontal run of a bank by employing a central support member and a side support member on each side of it.

The invention and advantages thereof will become more apparent on consideration of the following detailed description and accompanying drawings in which:

FIGURE 1 is a side elevation, partially fragmented, of a vapor generator utilizing the invention.

FIGURE 2 is an isometric view of the economizer of a vapor generator arranged in accordance with this invention.

FIGURE 3 is an enlarged isometric view of that portion of the economizer at which the right vertical stringer tubes separate into dependent up and down risers.

FIGURE 4 is a cross-sectional view along line 4-4 of FIGURE 3.

FIGURE 5 is a cross-sectional view along line 55 of FIGURE 2.

FIGURE 6 is a cross-sectional view along line 6-6 of FIGURE 2.

FIGURE 7 is an enlarged isometric view of a portion of the economizer where the horizontal and vertical partition wall tubes cross.

Referring now to the drawing and more particularly to FIGURE 1, burners 11 provide hot combustion gases within a vapor generator 13 of the once-through, supercritical design. The particular vapor generator design illustrated is purely by way of examples as this invention can be used with any number of vapor generator arrangements. The vapor generator 13 includes a furnace of radiant section 15, a pendant convection surface section 17 and a horizontal convection section 19. Located in the pendant convection section 17 are two secondary superheater banks 21, 23, and a secondary reheater bank 25.

The horizontal convection section 19 is lined with tubes 27 which extend between a lower header 31 and an upper header 29. The wall formed by the tubes 27 is of fin-tube construction to seal the combustion gases within the enclosure of the horizontal convection section 19. Within the horizontal convection section 19 are an upper primary superheater bank 33 and a lower primary superheater bank 35. Also located within the horizontal convection section 19 are an upper primary reheater bank 37, an intermediate primary reheater b ank 39, and a lower pri mary reheater bank 41. Beneath the primary reheater banks 37, 39, 41 and the primary superheater banks 33, 35, are economizer banks generally designated by numeral 43.

Still referring to FIGURE 1, the feedwater being fed to the economizer 43 enters through an economizer inlet header 45 located centrally in the horizontal convection section 19. The flow of fluid leaves the economizer inlet header 45 through two series of economizer tubes 47, 49, which together form a lower right economizer bank 51. The economizer tubes 47 continue horizontally at the top of the lower right economizer bank 51 across the horizontal convection section 19 and then loop downwardly to form a left economizer bank 53. The downstream end of the economizer tubes 47, located at the bottom of the left economizer bank 53 connect with an intermediate economizer header 55 located centrally within the horizontal convection section 19 directly above the economizer inlet header 45.

The series of economizer tubes 49 continues to loop upwardly from the lower right economizer bank 51 to form an upper right economizer bank 57. At the upper level of the upper right economizer bank 57, approximataly half of the series of economizer tubes 49 bend upwardly into upper right stringer tubes 59. The alternate tubes in the series of economizer tubes 49 bend downwardly into lower right stringer tubes 61. The upper right stringer tubes 59 and the lower right stringer tubes 61 are mechanically secured together to form a right vertical stringer 62 but not connected for flow purposes as will hereinafter be explained. The upper right stringer tubes 59 bend inwardly to connect with an economizer outlet header 63. The economizer outlet header 63 is located centrally directly above the economizer inlet header 45 and the intermediate economizer header 55 but at the upper end of the horizontal convection section 19.

The lower right stringer tubes 61 bend inwardly to connect with the intermediate economizer header 55. Thus, there are two series of tubes feeding into the intermediate economizer header 55; namely, the lower right stringer tubes 61, which represent alternate tubes in the series of economizer tubes 49, and the entire series of economizer tubes 47.

A series of central vertical stringer tubes 65, arranged as an all welded fin and tube partition wall, extends vertically between the intermediate economizer header 55 and the economizer outlet header 63. The number of tubes in the central vertical series 65 is substantially equal to the series of economizer tubes 47. A series of left vertical stringer tubes also connects the intermediate economizer header 55 with the economizer outlet header 63. The left vertical series 67 substantially equals the number of tubes in the lower right vertical series 61. The left vertical stringer 67 is symmetrically located about the central vertical stringer 65 with the right vertical stringer 62.

As previously explained, the upper right stringer tubes 59 and the lower right stringer tubes 61 are mechanically secured together but not connected for flow purposes. This connection can best be seen in FIGURES 3 and 4. Alternate tubes 64 of the economizer tubes series 49 loop back and forth in two horizontal passes and then bend straight upward into the upwardly flowing right stringer portion 59. The remaining alternate tubes 66 bend straight across once and then bend back over on a slant 68 before bending straight down to form the lower right stringer tubes 61. As best shown in FIG- ,URE 4, the slant 68 is also inclined at an angle to the' vertical plane in which the bend into it is located sorthat the upper right stringer tubes 59 and the lower right stringer tubes 61 are in close proximity permitting them to be rigidly secured together by a weld 69. The lower right stringer portion 61 thus passes the lower horizontal pass of the two loops 64, 66, and is also secured to both by a weld 71.

The details of the economizer tubes 47crossing the central vertical stringer 65 are shown in FIGURE 7. Located between the series central vertical stringer tubes 65'are fins 73 which form the central vertical stringers into a solid barrier wall. As seen in FIGURE 2, alternate tubes of the central vertical stringers bow out slightly at the upper end to form a gas flow passageway 75, through the, barrier wall, formed by the central vertical stringer'tubes 65 and the fins 73. Returning to FIG.- URE 7, it can be seen that both the central vertical stringers 65 and the economizer tubes 47 are alternately spaced with a tube space between each two adjacent tubes. An opening 74 in the fins 73 permits the economizer tubes 47 to pass through the central vertical stringers 65.

FIGURE 5 shows in detail the manner. in which theeconomizer tubes '47, 49 in the lower right economizer bank 51'cross at substantially right angles, the lower right stringer tubes 61. As also shown in FIGURE 3, the lower right stringer tubes 61 occupy every fourth tube space which can also be described as every other clear'space between tubes 47 and 49. Since the economizer .t-ubes 49 occupy every other tube space, each lowerv right stringer tube 61 occupies every other space open or clear space betweentwo adjacent economizer tubes 49. The right stringer portion 59 is secured to the economizer tubes by welds 79. The left vertical stringer tubes 67 cross the economizertubes 47- in the left economizerbank 53 in a manner similar to that shown in FIGURES.

As best seen in FIGURE 6, the economizer tubes 47, 49. as they extend vertically upward directly downstream of the economizer inlet header, 45 are located in every other vertical'tube space in a two loop arrangement with each tube 47 as the inside tube and with the two tubes 47, 49 lying in a common plane.

As should now be apparent, this invention provides a unique economizer construction in which three vertical stringers cooled by the relatively cool feedwater passing through an economizer serve to support not only the economizer banks themselves, but any superheater and reheater banks or'other tube configurations required within a vapor generator or the like. The supported tube banks may be clipped or welded to the stringers in any suitable manner.

Although the invention has herein described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example, and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. An economizer arrangement for useas a support means within a vapor generator, said economizer arrangement comprising:

a series of first economizer tubes and a series of second economizer tubes arranged for parallel flow;v

a series of left stringer tubes vertically oriented in a common vertical plane;

a series of right stringer tubes including a series of upper portions and a series of lower portions externally secured together, said series of right stringer tubes being located in a common vertical plane parallel to the common vertical plane of the series of left stringer tubes;

a series of central stringer tubes located intermediate the series of left stringer tubes and the series of right stringer tubes, said series of central stringer tubes being located in a common vertical plane parallel to the common vertical plane of the series of left stringer tubes;

means for connecting substantially one-half of the series of first economizer tubes to the upper portion of the series of right stringer tubes and for connecting the remaining half to the lower portion of the series of right stringer tubes; and,

means for connecting the lower portion of the series of right stringer tubes and the series of second economizer tubes to the series of left stringer tubes and the series of central stringer tubes.

2. An economizer arrangement according to claim 1 wherein the number of central stringer tubes is substantially twice the number of left stringer tubes, the number of left stringer tubes being substantially equal to the number of right stringer tubes.

3. An economizer arrangement according to claim 1 wherein the series of first economizer tubes and the series of second economizer tubes are arranged in a first bank supported by the series of right stringer tubes.

4. An economizer arrangement according to claim 3 further including a second bank of economizer tubes formed from the series of first economizer tubes and located directly above said first bank, said second bank being connected downstream of said series of first econornizer tubes in said first bank.

1 5. An economizer arrangement according to claim 4 further including a third bank of economizer tubes formed from the second series of economizer tubes and located directly along side said first bank, said third bank being connected downstream of said series of second economizer tubes in said first bank.

6. An economizer arrangement for use as a support means within a vapor generator, said economizer arrange- A ment comprising:

a first bank of economizer tubes located within a vapor generator; a second bank of economizer tubes located above said first bank of economizer tubes; a third bank of economizer tubes located beside said first bank of economizer tubes, said second and third bank having substantially the same number of tubes therein and each having substantially half the number of tubes as said first bank of economizer tubes, said second bank being connected downstream of approximately half the tubes in said first economizer bank, said third bank being connected downstream of the approximate remaining half of tubes in said first economizer bank;

right vertical stringer tubes extending through said first bank and said second bank said right vertical stringer tubes including lower tubes and upper tubes, said upper tubes being connected downstream of approximately half of the tubes in said second bank and said lower tubes being connected downstream of approximately the remaining half of the tubes in said second bank, said upper tubes and said lower tubes being externally secured together;

left vertical stringer tubes passing through said third bank, said left vertical stringer tubes numbering approximately the same as said right vertical stringer tubes; and,

' central vertical stringer tubes located intermediate said left vertical stringer tubes and said right vertical stringer tubes and numbering approximately twice the number of tubes as said left vertical stringer tubes and as said right vertical stringer tubes, said left vertical stringer tubes and said central vertical stringer tubes being connected downstream of said lower portion of said right vertical stringer and said third tube bank.

7. An economizer arrangement according to claim 6 wherein said right vertical stringer tubes and said left vertical stringer tubes and said central vertical stringer tubes each lie in a separate vertical plane which three separate vertical planes are substantially parallel to one another.

8. An economizer arrangement for use as a support means within a vapor generator, said economizer arrangement comprising:

a first bank of economizer tubes located within a horizontal convection section of a vapor generator, said first bank of economizer tubes including a first series of economizer tubes and a second series of economizer tubes;

an inlet header located at the lower end of the horizontal convection section, said first series of economizer tubes and said second series of economizer tubes being connected to said inlet header so that said first series of economizer tubes and said second series of economizer tubes are adapted for parallel -fiow with one another;

a second bank of economizer tubes located above said first bank of economizer tubes; said second bank of economizer tubes being a continuation of said second series of economizer tubes in said first bank of economizer tubes;

an intermediate header located at the lower end of the horizontal convection section;

a third bank of economizer tubes located beside said first bank of economizer tubes, said third bank of economizer tubes being a continuation of said first series of economizer tubes in said first bank of economizer tubes, said third bank of economizer tubes being connected at its downstream end to said intermediate header;

an outlet header located at the upper end of the horizontal convection section;

right vertical stringer tubes extending vertically through said first bank and said second bank, said right vertical stringer tubes including lower tubes and upper tubes, said upper tubes being a continuation of alternate tubes of said second series of economizer tubes in said second bank of economizer tubes, said lower tubes being a continuation of the remaining alternate tubes of said second series of economizer tubes in said second bank of economizer tubes, said upper tubes being connected at their upper end to said outlet header and said lower tubes being connected at their lower end to said intermediate header, each of said upper tubes being secured externally to one of said lower stringer tubes;

left vertical stringer tubes extending vertically through said third bank of economizer tubes, said left vertical stringer tubes being connected at their upper ends to said outlet header and at their lower ends to said intermediate header, said left vertical stringer tubes numbering approximately the same as said right vertical stringer tubes; and,

central vertical stringer tubes located intermediate said left vertical stringer tubes and said right vertical stringer tubes and numbering approximately twice the number of tubes as said left vertical stringer tubes and as said right vertical stringer tubes, said central vertical stringer tubes being connected at their upper ends to said outlet header and at their lower ends to said intermediate header, said right vertical stringer tubes and said left vertical stringer tubes and said central vertical stringer tubes each lying in a separate vertical plane which three vertical planes are substantially parallel to one another.

9. An economizer arrangement for use as a support means within a horizontal convection section of a vapor generator, said economizer arrangement comprising:

a lower right bank of economizer tubes located in the lower right space of a horizontal convection section of a vapor generator, said lower right bank of economizer tubes including a first series of economizer tubes and a second series of economizer tubes; each tube of said first series being in common plane with a tube of said second series with both series arranged in a loop in loop configuration with the first series on the inside;

an inlet header located centrally at the lower end of the horizontal convection section, said first series of economizer tubes and said second series of economizer tubes being each directly connected to said inlet header so that said first series of economizer tubes and said second series of economizer tubes are adapted for parallel flow with one another;

an upper right bank of economizer tubes located on the right side of the horizontal convection section above said lower right bank, said upper right bank of economizer tubes being formed exclusively by a continuation of all of said second series of economizer tubes in said lower right bank of economizer tubes;

an intermediate header located centrally at the lower end of the horizontal convection section but above the inlet header;

a left bank of economizer tubes located on the left side of the horizontal convection section along side said lower right bank of economizer tubes, said left bank of economizer tubes being formed exclusively by a continuation of all of said first series of economizer tubes in said lower right bank of economizer tubes, said left bank of economizer tubes being connected at its lower and downstream end to said intermediate header;

an outlet header located centrally at the upper end of the horizontal convection section above the inlet header and the intermediate header;

right vertical stringer tubes extending vertically from top to bottom on the right side of the horizontal convection section and passing through said lower right bank of economizer tubes and said upper right bank of economizer tubes, said right vertical stringer tubes including lower stringer tubes and upper stringer tubes, said upper stringer tubes being a continuation of alternate tubes of said second series of economizer tubes in said upper right bank of economizer tubes, said lower stringer tubes being a continuation of the remaining alternate tubes of said second series of economizer tubes in said upper right bank of economizer tubes, said upper stringer tubes being connected at their upper end to said outlet header and said lower stringer tubes being connected at their lower end to said intermediate header, each one of said upper st-ringer tubes being secured externally to one of said lower stringer tubes;

le-ft vertical stringer tubes extending vertically from top to bottom on the left side of the horizontal convection section and passing through said left bank of economizer tubes, said left vertical stringer tubes being connected at their upper ends to said outlet header and at their lower end to said intermediate header, said left vertical stringer tubes numbering approximately the same as said right vertical stringer tubes;

central vertical stringer tubes extending vertically from top to bottom centrally within the horizontal convection section said central vertical stringer tubes being connected at their upper ends to said outlet header and at their lower ends to said intermediate header, said central vertical stringer tubes numbering approximately twice the number of tubes as said left vertical stringer tubes and as said right vertical strin-ger tubes, said left vertical stringer tubes lying in a common vertical plane, said right vertical stringer tubes lying in a common vertical plane, said central vertical stringer tubes lying in a common plane, all three of said common planes being parallel to one another, said right vertical stringer tubes and said left vertical stringer tubes being substantially symmetrically spaced about said central vertical stringer tubes; and

opening therein at its upper end to permit gas flow through the barrier wall.

References Cited by the Examiner UNITED fins located between said central vertical stringer tubes 10 KENNETH W. SPRAGUE Primary Examiner to form a barrier wall said barrier wall having an 

1. AN ECONOMIZER ARRANGEMENT FOR USE AS A SUPPORT MEANS WITHIN A VAPOR GENERATOR, SAID ECONOMIZER ARRANGEMENT COMPRISING: A SERIES OF FIRST ECONOMIZER TUBES AND A SERIES OF SECOND ECONOMIZER TUBES ARRANGED FOR PARALLEL FLOW; A SERIES OF LEFT STRINGER TUBES VERTICALLY ORIENTED IN A COMMON VERTICAL PLANE; A SERIES OF RIGHT STRINGER TUBES INCLUDING A SERIES OF UPPER PORTIONS AND A SERIES OF LOWER PORTIONS EXTERNALLY SECURED TOGETHER, SAID SERIES OF RIGHT STRINGER TUBES BEING LOCATED IN A COMMON VERTICAL PLANE PARALLEL TO THE COMMON VERTICAL PLANE OF THE SERIES OF LEFT STRINGER TUBES; A SERIES OF CENTRAL STRINGER TUBES LOCATED INTERMEDIATE THE SERIES OF LEFT STRINGER TUBES AND THE SERIES OF RIGHT STRINGER TUBES, SAID SERIES OF CENTRAL STRINGER TUBES BEING LOCATED IN A COMMON VERTICAL PLANE PARALLEL TO THE COMMON VERTICAL PLANE OF THE SERIES OF LEFT STRINGER TUBES; MEANS FOR CONNECTING SUBSTANTIALLY ONE-HALF OF THE SERIES OF FIRST ECONOMIZER TUBES TO THE UPPER PORTION OF THE SERIES OF RIGHT STRINGER TUBES AND FOR CONNECTING THE REMAINING HALF TO THE LOWER PORTION OF THE SERIES OF RIGHT STRINGER TUBES; AND MEANS FOR CONNECTING THE LOWER PORTION OF THE SERIES OF RIGHT STRINGER TUBES AND THE SERIES OF SECOND ECONOMIZER TUBES TO THE SERIES OF LEFT STRINGER TUBES AND THE SERIES OF CENTRAL STRINGER TUBES. 